The present invention relates to a coolant fed humidifier, particularly cool water, having a siphon drain.
Many humidifiers generate water vapor for heat, ventilation and air conditioning (HVAC) systems by heating water to a boiling temperature and thereby suppling airborne water vapor to the HVAC system in a building. These types of humidifiers sometime suffer from the accumulation of minerals and other water borne particles or elements. In order to continue the efficient operation of this type of humidifier, the humidifier tank is periodically flushed or filled with water from a water supply or water source. Water from the source is usually at a much lower temperature, typically the ambient temperature, and hence, cooler than water in the humidifier tank. Accordingly, it is proper to call this water from the source xe2x80x9ccoolantxe2x80x9d or xe2x80x9ccool water.xe2x80x9d
The control system which triggers the fresh water rinse can use many parameters such as periodic time frames, the amount of input water, seasonal drain cycles, the number of times the water in the humidifier exceeds a certain level or the amount of foam in the humidifier. The present invention can be utilized in conjunction with many types of control systems.
Government regulations in some jurisdictions now require that water from the humidifier tank only be discharged at or below a certain predetermined temperature. In some jurisdictions, the discharged water temperature may not exceed 140xc2x0 Fahrenheit. The typical temperature in a water humidifier is 212xc2x0 Fahrenheit when the humidifier is active.
Accordingly, there is a need to provide a mechanism to chill or reduce the temperature of the water in the humidifier tank prior to discharging the water from the tank.
Also, the cost of additional valving is a factor in the production of humidifier systems. The more valves utilized in a humidifier system, the higher the cost. The utilization of additional valves requires additional maintenance. Additional control circuitry and control wiring must also be employed with additional valves. Hence, there is a need for a humidifier system which lowers the tank water temperature to acceptable levels and automatically flushes the system without the need for additional valves and valve control systems.
Nothing in the prior art provides solutions to these problems. For example, U.S. Pat. No. 3,612,033 to Chilcoat discloses a humidifier with a siphon draining a drain off reservoir which is distinct from the humidifier tank. U.S. Pat. No. 3,716,043 to Chilcoat has a similar drain off reservoir.
U.S. Pat. No. 3,643,930 to Schulze discloses a humidifier tank fed with source fluid and an inverted U-shaped siphon drain from the tank. Source fluid, under control, sometimes flushes the tank by raising the fluid level in the tank above the height of the inverted U-shaped siphon thereby causing an automatic siphon drain of the tank fluid. U.S. Pat. No. 3,739,597 to Schulze has a similar automatic siphon.
U.S. Pat. No. 4,243,396 to Cronenberg uses a siphon tube to draw up liquid from a lower liquid source.
U.S. Pat. No. 4,705,936 to Fowler discloses an inverted U-shaped siphon from a boiling tank leading to an adjacent drain tank at the same level as the boiling tank. The fill tube feeding the boiling tank is distinct from the automatic siphon.
It is an object of the present invention to provide a coolant fed humidifier having an automatic siphon drain.
It is an additional object of the present invention to provide a humidifier which is fed with cooler source water, thereby reducing the temperature of the water in the humidifier tank and then automatically draining the tank water once the tank water exceeds a predetermined level in the tank.
It is a further object of the present invention to provide a humidifier with an automatic siphon drain thereby eliminating additional valves.
It is another object of the present invention to provide a humidifier tank flushing system in which the humidifier tank water is admixed with cooler water, thereby reducing the water temperature of the admixture prior to siphoning and draining the water, and that is also capable of admixing additional cooler water into the admixture as it is being drained through the siphon action such that the new admixture resultant is yet at a lower temperature.
It is a further object of the present invention to provide a method of draining a hot water humidifier.
A hot water humidifier with an automatic siphon drain fed with cooler source water is flushed via a drain. The hot water humidifier includes a humidifier tank supplied with the cooler source water. The automatic siphon is an inverted substantially U-shaped siphon conduit automatically operable with respect to the humidifier tank having one end coupled to the tank and the other end coupled to the drain. The humidifier also includes a source conduit coupled to and feeding the cooler source water to the humidifier tank. A valve controlling the cooler source water feeds the source water into the humidifier tank to maintain the temperature of an admixture of cooler source water and any preexisting tank water at or below a predetermined temperature during a flush cycle. The tank is flushed and drained via the automatic siphon based upon the level of the admixture in the tank and the level of admixture in the siphon. The source conduit which feeds water to the tank may be coupled to the humidifier tank via the siphon conduit. The apex of the siphon conduit is positioned at a level above the end of the siphon conduit coupled to the humidifier tank. The source conduit may also be coupled to the humidifier tank in more than one location to promote admixing of the cooler source water with the hot water in the tank. A temperature sensor may also be disposed within any of the areas containing the admixture, including the tank and associated conduits, to provide feedback to the valve controlling the input of source water into the system. In addition, cooler source water may be added to the admixture as it is draining during the siphon action in order to further lower the temperature of the admixture.
A method of draining a hot water humidifier having a humidifier tank supplied with cooler source water is also included. The method includes admixing the cooler source water in the tank with the hot water until the admixture reaches a predetermined siphon height and is less than a predetermined temperature, and thereafter, automatically siphoning and draining the admixture until the admixture reaches a lower siphon exhaustion height.